Hello, again!
Apparently, there is a "50th Anniversary Restoration" done at high resolution. Does anyone know if that's the one used for the BD? The Blu-ray having been released months after the screening would seem to indicate so, but studios have been known to do illogical things in the past. And a 4k of the original camera negative should look better than what the BD reviewers seem to indicate.
http://silverscreenoasis.com/oasis3/viewtopic.php?f=1&t=4260&start=360
• The Great Escape (1963) – World Premiere of 50th Anniversary Restoration
(...) The Great Escape was restored by Metro Goldwyn Mayer Studios at Deluxe Digital Media using a 4K scan of the original camera negative.
And about the seeding: perhaps you're not connectable ( like me ), which means about only half the people can actually connect to you. But if you hang on in there, a connectable member will show up and act like a bridge between you and the rest.